Ship project history: Fast landing transports, projected specially for supply delivery to isolated island garrisons.
They had original enough hull with "inverse" deck sheer: at aft end
the deck was smoothly dropped to a water-line that allowed to launch vehicles and
landing crafts by two special roller ways.
Disemarkation could be effected both on stop, and on up to 16kts speed.
For cargo storage ships were arranged with two holds amidships. Cconstruction was as much as possible simplified for simplification of
building.

The order for such 46 ships has been given out in September, 1943. Till the end of war 21
ships were commissioned, building of one (Ò22) was suspended in June, 1945 in 90% availability.
Orders for 24 more were cancelled in May, 1945.

1945, all completed and survived: military load can
include 2 Koryu midget submarines or 6 Kaiten human torpedoes

Naval service: Ò1 was sunk 27/7/1944
by American carrier aircraft off Palau. Ò4 was sunk 4/8/1944 by American carrier aircraft
off Chichijima. Ò2 was sunk 5/8/1944 by American carrier aircraft off Chichijima.
Ò5 was sunk 14/9/1944 by
American carrier aircraft off Mindanao. Ò3 was sunk 15/9/1944 by American submarine
Guavina off Mindanao. Ò6 and Ò10 were sunk 25/11/1944 by American
carrier aircraft in Balanacan harbour. Ò11 was sunk 7/12/1944 by American aircraft
off Leyte. Ò12 was sunk 13/12/1944
by American submarine Pintado in 200nm SE off Takao.
Ò8 was sunk 24/12/1944
by American destroyers Case and Roe
off Chichijima. T7 was sunk 27/12/1944 by American destroyers
Dunlap, Fanning
and Cummings off Kazan. Ò14 was sunk 15/1/1945 by American
carrier aircraft off Takao. Ò15 was sunk 17/1/1945 by American submarine
Tautog off Kagoshima, Kyushu. T18 was sunk 18/3/1945
by American submarine Springer near Mutsurejima, NW part of
Kyushu. Ò17 was sunk 2/4/1945
by American carrier aircraft off Amami. Ò21 was hard damaged 9/8/1945 by American Army aircraft
and sunk next day off Tsuwajima.

T20 was used in repatriation service
and ran aground 25/9/1946 off Chipei-Hsiaotao (Pescadores).